Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 76, Issue 1
Displaying 1-2 of 2 articles from this issue
  • Importance of the magnetic coupling with the outer core
    Shun-ichiro KARATO
    2000 Volume 76 Issue 1 Pages 1-6
    Published: 2000
    Released on J-STAGE: October 17, 2006
    Macroscopic processes which may be responsible for the anisotropic structure in the Earth's inner core are examined. It is concluded that the magnetic interaction with the outer core plays the most important role in the dynamics of the inner core. Deformation due to the magnetic interaction causes cumulative strain at least for a period of one magnetic polarity (-0.1-10my), and can result in a large strain (-1-103) leading to the formation of anisotropic structures. The flow caused by the magnetic field results in continuing melting and solidification at the inner-outer core boundary which gives rise to a large energy release (or absorption). The present model shows that the pattern of energy release (or absorption) due to this mechanism is consistent with that of dynamo models, indicating that the energy release (or absorption) caused by this mechanism enhances convection in the outer core and hence stabilizes the magnetic field which is otherwise highly unstable.
    Download PDF (3250K)
  • Takumi AKAGI, Tsutomu HASHIKAWA, Keiji HIRAI, Ion MOTELICA-HEINO, Shig ...
    2000 Volume 76 Issue 1 Pages 7-11
    Published: 2000
    Released on J-STAGE: October 17, 2006
    During electrical stimulation of the frog neuromuscular preparation in Ringer solution, CaCl2 (1.8mM) was replaced by equimolar CoCl2 (Co-Ringer solution). Muscular contraction due to the motor nerve stimulation was blocked completely within 2min, while muscular contraction due to direct muscle stimulation was reduced but not completely blocked. The tissue was fixed with 2.5% glutaraldehyde prepared in Co-Ringer solution. After rapid wash in Ringer solution, the tissue was transfered into an aqueous solution containing 10mM K3Fe(CN)6 (precipitating agent of Co2+) and 90mM NaCl. In conventional transmission electron microscopy, large precipitates were observed close to both sides of the presynaptic membrane, outside of the sarcolemma in subsynaptic and extrasynaptic area, on the myofibrils and close to both sides of the membrane of the sarcoplasmic reticulum in the vicinity of the T-tubules. It is presumed that the sites where the precipitates were localized correspond to the voltage dependent calcium channels of the presynaptic membrane, sarcoplasmic membrane and membrane of sarcoplasmic reticulum. The precipitates found on the myofibrils are considerd as Co2+ which penetrated the endplate channels and directed towards the sarcoplasmic reticulum. To our knowledge, the present electron microscopic observation of Co2+ precipitatedwith potassium ferricyanide is the first attempt in the cobalt cytochemistry.
    Download PDF (4840K)